Université de Neuchâtel

The kinetics and mechanism of oxidation of isopropanol with the hydrogen peroxide-vanadate ion-pyrazine-2-carboxylic acid system

Romakh, Vladimir B. ; Kozlov, Yuriy N. ; Süss-Fink, Georg ; Shul’pin, Georgiy B.

In: Russian Journal of Physical Chemistry A, Focus on Chemistry, 2007, vol. 81, no. 8, p. 1221-1229

The vanadate anion in the presence of pyrazine-2-carboxylic acid (PCA) was found to effectively catalyze the oxidation of isopropanol to acetone with hydrogen peroxide. The electronic spectra of solutions and the kinetics of oxidation were studied. The conclusion was drawn that the rate-determining stage of the reaction was the decomposition of the vanadium(V) diperoxo complex with PCA, and the...

Université de Neuchâtel

Vanadate ion-catalyzed oxidation of methane with hydrogen peroxide in an aqueous solution

Romakh, Vladimir B. ; Süss-Fink, Georg ; Shul’pin, Georgiy B.

In: Petroleum Chemistry, 2008, vol. 48, no. 6, p. 440-443

It was shown that, unlike methane oxidation with the reagent “hydrogen peroxide-vanadate anion-pyrazine-2-carboxylic acid (PCA)” in acetonitrile, the performance of the process in an aqueous solution is accompanied by the intense parallel degradation of the cocatalyst. Therefore, relatively high yields of methane oxidation products (largely, formic acid) cannot be attained unless a rather...

Université de Neuchâtel

Regioselective alkane oxygenation with H2O2 catalyzed by titanosilicalite TS-1

Shul’pin, Georgiy B. ; Sooknoi, Tawan ; Romakh, Vladimir B. ; Süss-Fink, Georg ; Shul’pina, Lidia S.

In: Tetrahedron Letters, 2006, vol. 47, no. 18, p. 3071-3075

Titanosilicalite TS-1 catalyses oxidation of light (methane, ethane, propane and n-butane) and normal higher (hexane, heptane, octane and nonane) alkanes to give the corresponding isomeric alcohols and ketones. The oxidation of higher alkanes proceeds in many cases with a unique regioselectivity. Thus, in the reaction with n-heptane the CH2 groups in position 3 exhibited a...

Université de Neuchâtel

Dinuclear manganese complexes containing 1,4-dimethyl-1,4,7-triazacyclononane ligands as well as carboxylato and oxo bridges

Romakh, Vladimir B. ; Therrien, Bruno ; Karmazin-Brelot, Lydia ; Labat, Gael ; Stoeckli-Evans, Helen ; Shul’pin, Georgiy B. ; Süss-Fink, Georg

In: Inorganica Chimica Acta, 2006, vol. 359, no. 5, p. 1619-1626

The reaction of 1,4-dimethyl-1,4,7-triazacyclononane (L-Me2) with MnCl2 • 4H2O in acetonitrile gives, in the presence of sodium formate, hydrogen peroxide, triethylamine and KPF6, the dinuclear Mn(III)–Mn(IV) complex cation [(L-Me2)2Mn2 (O) 2 (OOCH)]2+ (1) which crystallises as the...

Université de Neuchâtel

Dinuclear iron, ruthenium and cobalt complexes containing 1,4-dimethyl-1,4,7-triazacyclononane ligands as well as carboxylato and oxo or hydroxo bridges

Romakh, Vladimir B. ; Therrien, Bruno ; Labat, Gael ; Stoeckli-Evans, Helen ; Shul’pin, Georgiy B. ; Süss-Fink, Georg

In: Inorganica Chimica Acta, 2006, vol. 359, no. 10, p. 3297-3305

The reaction of 1,4-dimethyl-1,4,7-triazacyclononane (L–Me2) with FeSO4 • 7H2O in aqueous ethanol gives, in the presence of sodium carboxylates, hydrogen peroxide, sodium hydroxide and KPF6, the dinuclear Fe(III)–Fe(III) complex cations [(L–Me2)2Fe2(O)(OOCR) 2]2+ (R = H: 1, R = CH3:...

Université de Neuchâtel

Supramolecular cluster catalysis : facts and problems

Süss-Fink, Georg ; Therrien, Bruno ; Vieille-Petit, Ludovic ; Tschan, Mathieu J.-L. ; Romakh, Vladimir B. ; Ward, Thomas R. ; Dadras, Massoud ; Laurenczy, Gabor

In: Journal of Organometallic Chemistry, 2004, vol. 689, p. 1362-1369

By checking the chemistry underlying the concept of "supramolecular cluster catalysis" we identified two major errors in our publications related to this topic, which are essentially due to contamination problems. (1) The conversion of the "closed" cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) into the...